a {
    background-image: url(data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7);
    background-image: url("./image (1).jpg");
    background-image: url('./image (1).jpg');
    background-image: URL('./image (1).jpg');
    background-image: url(   './image (1).jpg');
    background-image: url('./image (1).jpg'   );
    background-image: url(   './image (1).jpg'   );
    background-image: url(   
    './image (1).jpg'   
    );
    background-image: url();
    background-image: url(   );
    background-image: url("");
    background-image: url(   ""   );
    background-image: url('');
    background-image: url(   ''   );
    background-image: url(   ' '   );
    background-image: url(./image.png);
    background-image: url(   ./image.png   );
    background-image: url(   ./image\32.png   );
    background-image: url(   
    ./image\32.png   
    );
    background-image: url(
    
    
    
       ./image\32.png
    
    
    
    );
    background-image: url(   



    ./image\32.png



       );
    background: url(image.png\0001);
    background: url(image.png\1);
    background: url(image.png\D799);
    background: url(image.png\E000);
    background: url(image.png\10FFFF);
    background: url(18);
}